If you install a virtual audio driver such as Blackhole, ASIO, or Soundflower, you can select that driver as the audio output in your music software, and as the audio input on the Blast Radio Desktop App. This will enable you to broadcast audio from those programs directly onto Blast Radio. If your software accepts plugins (most DAWs do) then we suggest using the Blast Radio DAW Plugin instead of the Desktop Broadcasting App.
The Blast Radio Desktop Broadcasting App and the DAW Plugin come in the same installer package together and will automatically install onto your laptop/computer. If you want to access the DAW Plugin, you need to launch a DAW like Garage Band, FL Studio, ProTools, Logic, Ableton etc. that accepts plugins. Check here on how to use the Blast Radio DAW Plugin with a DAW.